Each week I keep a running list of great viral videos I stumble upon, which I then use as the basis for this weekly column. This week’s list is the longest yet—in almost a year of doing this—with nearly 20 videos that are deserving of mention and further study. Needless to say, I had a hard time choosing, because there are many great lessons for us to learn from the videos that succeeded in going viral this week.

Let’s dive in:

The Chatroulette Con

I am so impressed with the marketing folks behind the campaign for The Last Exorcism—a horror film from Lionsgate that comes out August 27. You might have see the trailer for this film on Inception, as I did. I remember thinking… “Gee, there’s another horror movie I don’t really care about.” But I am not generally a horror fan anyway, so that shouldn’t be taken as a sign that I thought it looked awful or anything.

Anyway, Chatroulette is an incredibly popular service that puts users into a video chat with random strangers. Hilarity often occurs. Sometimes perversion occurs as well, though Chatroulette is working hard to curb that kind of behavior. The first great example of someone using the chat site to their own advantage came in January of this year, when Merton burst onto the scene (don’t miss our interview-in-song with Merton). He created improvised songs about the people he was randomly paired with, and has gone on to many millions of views.

Now, a Hollywood movie has upped the Chatroulette-marketing ante, by preying on the site’s early reputation as a place where people undressed for each other. Random chatters were paired with a pretty gal, who appeared at first to be willing to disrobe. Suddenly, though, she stops… and freaky things start happening—exorcism-type freaky things. And the reactions are fairly priceless. Check it out:

This video is going viral—over a quarter of a million views in two days—for some pretty obvious reasons. First, it’s funny. Like any practical joke or hidden camera piece, the surprise in the faces of the unsuspecting victims is pretty hilarious. They go from excited about seeing a hot girl to frightened-for-their-lives in a matter of seconds.

Second, it’s got the element of surprise. Raise your hand if you’ve ever enjoyed a good haunted house in your day. Ahh… I see lots of hands. That’s what I thought. We enjoy seeing scary things, and we enjoy seeing other people get scared. Toss in the fact that Chatroulette is typically for live chats—and the users don’t always expect anything other than a live person on the other end—and the element of surprise is compounded.

Thirdly, this video (and the stunt that the video was created from) is actually a mirror of the thing it’s promoting. A horror movie, which aims to scare you, uses a marketing gimmick that scares you.

Think about how easy and inexpensive this must have been for the studio to create. Just film one or two new scenes of a girl appearing to chat online… throw in some basic makeup effects… and then leverage Chatroulette’s pre-existing platform and user base to craft the marketing video. Brilliant. No two ways about it.

The Simple Animation

Simon’s Cat is an ongoing cartoon series from animator Simon Tofield. I’ve been watching them ever since the first one appeared on YouTube two years ago. He’s built up a pretty loyal following, and sites like Cute Overload or ICanHasCheezburger typically help him get viewers by posting the videos for their readers.

If you’ve never seen Simon’s Cat, it’s well worth a look. If you have seen the previous videos, you don’t want to miss this one:

What makes the Simon’s Cat video so great—and so appealing to pet lovers and cat fans—is how clear a grasp Tofield has on cat behavior. The only real way to explain what I mean is to say this: If you own a cat, it will be abundantly obvious to you upon watching these videos that Simon Tofield has owned cats too. He just absolutely nails the behavior, as his channel’s 75 million views will attest.

The video is funny—with the sound effects playing a big role in achieving that humor. And the fact that he focuses on common qualities of cats—like their strange obsession with boxes, or the way they’re always asking for more food—helps his target audience instantly identify with his characters.

There’s also a good lesson in here about simplicity. Both the concepts and the execution of these cartoons is simple, which works because they are also solid. He’s not trying to clutter it up with unnecessary imagery or sound or complicated plot twists. Heck, it’s even in black and white, for Pete’s sake.

There are a lot of things we can learn from Mr. Tofield, actually. He’s used these videos to launch an entire enterprise around the characters, complete with a book, a gift shop, and even an iPhone app. He knows his audience, and his subjects, and doesn’t stray far from a proven winning formula.

The Pop-Culture Reference

We continue to see great evidence that piggybacking your viral video onto a current trend or hot-button issue is fantastic strategy. When a topic or event or person is high on the radar of the national consciousness, there is increased interest in anything related to it—including a spike in blog mentions, news articles, Google searches, Tweets, and more.

And the recent Jet Blue fiasco—where the steward spewed some foul language and then fled the plane via the emergency inflatable slide—is still on everyone’s mind. Late night talk show hosts are still making jokes about it, and now politicians are getting into the act.

The Republican National Committee has created and released a new commercial that is critical of President Obama, suggesting that even members of his own Democratic party are trying to distance themselves from him. And they’ve used the Jet Blue incident to make their point. Take a look:

Now, I hope you know by now that I’m not here to take sides politically. In fact, you don’t have to agree with the ad’s message to see that it was clever, timely, and well-made.

In 2010 alone, we’ve seen countless videos go viral by referencing or leveraging a current event (like Iron Baby, iPad Will It Blend, or Ben Folds’ Ode To Merton). It is one of the most reliable and proven formulas for viral success. The one caveat is that you typically have to move pretty fast to capitalize on a topic or story’s popularity, which means a rushed timetable for scripting, shooting, editing, and marketing your video.

Honorable Mention (Extra Long Edition)

Can’t leave any out, so I’m dumping the rest here in the Honorable Mention section. If I had more time, I would also have discussed:

Jeremy Scott is the founder of The Viral Orchard, an Internet marketing firm offering content writing and development services, viral marketing consulting, and SEO services. Jeremy writes constantly, loves online video, and enjoys helping small businesses succeed in any way he can.